Kitty cloning. They say people don't understand that the cloned cat is not the same as the original. But I suspect it would be pretty darn close, particularly if you raised it in the same household. A cat's breed determines quite a bit of its personality (loyal Russian Blues, gregarious Abyssinians, gentle Ragdolls, our Kaylee and Zoe--with same upbringing, different fathers, and very different personalities) and the upbringing does most of the rest.
On the other hand, the $50,000 spent to clone a cat could get you a wonderful pound kitten plus pay for spaying, neutering and veterinary care for hundreds of strays. I miss Sam every day, but I wouldn't have preferred a Sam clone to any of our subsequent kitties.